EGU2020-1682
https://doi.org/10.5194/egusphere-egu2020-1682
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Volcanic degassing along the enigmatic South Sandwich volcanic arc

Emma Liu1, Kieran Wood2, Alessandro Aiuppa3, Gaetano Giudice4, Marcello Bitetto3, Tom Pering5, Thomas Wilkes5, Andrew McGonigle5, Brendan McCormick Kilbride6, Tobias Fischer7, Scott Nowicki7, Emily Mason8, Tom Richardson2, and Tom Hart9
Emma Liu et al.
  • 1University College London, Earth Sciences, London, United Kingdom of Great Britain and Northern Ireland (emma.liu@ucl.ac.uk)
  • 2University of Bristol, Aerospace Engineering, Bristol, UK
  • 3University of Palermo, Dipartimento di Scienze della Terra e del Mare, Palermo, Italy
  • 4INGV, Sezione di Catania, Italy
  • 5University of Sheffield, Geography, Sheffield, UK
  • 6University of Manchester, Earth and Environmental Sciences, Manchester, UK
  • 7University of New Mexico, Albuquerque, US
  • 8University of Cambridge, Earth Sciences, Cambridge, UK
  • 9University of Oxford, Zoology, Oxford, UK

The South Sandwich Islands (SSI) are a chain of active volcanoes in the Southern Ocean and remain one of the most remote and enigmatic island arcs on Earth. The relatively recent development of the SSI over the past 20 million years has been closely linked with the formation of the Drake Passage, making this one of the youngest known volcanic arcs and therefore one of the most critical for understanding the early stages of arc geochemical evolution. Recent volcanic eruptions in the SSI have had significant impacts on local terrestrial and marine ecosystems, including some of the largest penguin colonies ever observed, through tephra deposition and from sustained volcanic degassing. Rare cloud-free satellite images over the last two decades have indicated that the summit of Mt Michael (Saunders) hosts a sustained lava lake, but until now these observations have not been ground-truthed by in-situ measurements. Long-term persistent passive outgassing at many of these volcanoes, even between eruptive phases, suggests that the SSI volcanic arc could be a significant source of volatiles to our atmosphere, and yet we lack any constraints on the degassing budgets of this volcanic arc. Here, we present novel measurements of gas chemistry, aerosol composition, and carbon isotope signature from along the South Sandwich Island arc. By combining ground-based measurements of SO2 flux with in-situ samples of plume composition using Unoccupied Aerial Systems (UAS), we present multi-species volatile fluxes for the major along-arc degassing sources. Further, by evaluating the carbon to sulfur ratio (C/ST) and carbon isotope composition in emitted gases together with petrological constraints from erupted tephra, we aim to test the hypothesis that carbon is supplied to the SSI by subduction of oceanic carbonated serpentinite, and thus contribute to our understanding of carbon recycling at subduction zones.

How to cite: Liu, E., Wood, K., Aiuppa, A., Giudice, G., Bitetto, M., Pering, T., Wilkes, T., McGonigle, A., McCormick Kilbride, B., Fischer, T., Nowicki, S., Mason, E., Richardson, T., and Hart, T.: Volcanic degassing along the enigmatic South Sandwich volcanic arc, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1682, https://doi.org/10.5194/egusphere-egu2020-1682, 2019

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